'How I Met Your Mother': When Robin says 'I love you...'

On this week's episode, Robin suspected that Barney was playing the perfect boyfriend because he was cheating on her. Robin had good reason. Barney, who earlier in the episode turned President Obama's campaign slogan “Yes, we can” into a pick-up line, isn't exactly known for bringing his one-night stands breakfast in bed. But Robin is not without her neuroses here.

Remember when she suspected Ted of cheating after their first fight as a couple back in Season 2?

Marshall ends up spilling the beans about Barney's “cheating” after Robin and Lily find a notebook in Barney's suitcase. The poor guy tries to save his slip with a compliment.

“Did you two ladies lose some weight?” he asks. A nod to his female costars' decidedly less pregnant states this season?

Turns out Barney isn't cheating on Robin with another girl, but he is cheating on their relationship. Now that they're officially dating – did I miss the class where the twosome decided to stop pretending? – Barney's enrolled in Robin 101, a class on how to date Robin Scherbatsky taught by the guy who lived to tell about it, Ted Mosby. That's a feat when you consider Robin punched Ted and made him cry. Most valuable lesson of Robin 101: When you see Robin's angry face, run the other way. At least she wasn't packing heat.

Despite wanting “his testicles attached to his body rather than rolling around next to some eyeliner in Robin's purse” and a case of ADHD so bad he can't even spell out the whole acronym before getting distracted by Twitter, Barney dutifully takes notes. Ted teaches him about Robin's facial expressions, topics to distract an angry Robin (the Vancouver Canucks, gun maintenance and the fancy mating etiquette of emperor penguins) and her surprising erogenous zones. While the first two lessons are useful, Robin sets Ted straight about her erogenous zones. If he really believed Robin's left knee was one of them, then he needs to enroll in Sex 101.

The most insightful lesson comes when Ted gives Barney a pop quiz, revealing the Robin will never be happy even if she becomes a famous TV journalist. What she really wants is to hear her father say, “Robin, I'm proud of you, eh.”

Ted's words seem to prove second-best after she busts the guys and an auditing student, who has a surprisingly good grasp on what's going on despite Ted's claim that he doesn't understand English.

“I've seen Barney work very hard to get women. I've seen him work very hard to get rid of women. I've never seen him work this hard to keep one around,” Ted says, comparing his stored-up Robin Scherbatsky knowledge to “the emotional equivalent of an English degree.”

In the end, Barney admits he was scared Robin was going to dump him, and Robin shakes her head, smiles and tells him he's an idiot. Earlier in the episode, Ted told Barney this is her way of saying “I love you,” whereas “I love you” means she's already broken up with you in her head.

The episode was very heavy on the Robin and Barney relationship drama, relegating Marshall and Lily to the sidelines. Lily played the supportive friend and revealed that Robin has made an occasional guest-star appearance in her dreams, reminding her “that a woman's sexuality is a moving target.” Marshall misses the confession by a second, lumbering into Ted's and Robin's apartment with Mabel the Barrel.

Mabel used to be Marshall's nightstand until Lily developed a sudden, inexplicable allergy to barrel resin. Freed from the building storage unit, Mabel's being put out on the street in the Bermuda triangle, otherwise known as a curb outside the apartment so magical that even a crappy couch is snatched in minutes. Unfortunately, its powers don't seem to apply to Mabel, which not only gets left standing but is also peed on by a dog. Barney's Cliff's Notes on dating Robin, however, are snapped up.

Somewhere, somebody is learning a lot of useless information about Robin's erogenous zones.